Measurement and calculation of the dimensions of the corrugated box structure design

1. Measurement of corrugated box size

Here, let us introduce the description of the size of the corrugated box:

a. Internal dimension: the size of the internal space after the corrugated box is in the box;

b. External dimensions: the outer contour size of the corrugated box after it is boxed;

c. Manufacturing dimensions: the dimensions used by the corrugated box during the manufacturing process;

In the measurement of the corrugated box, although the specific size can be directly measured by the tool, in the measurement process, the measurement result is not accurate due to the influence of the indentation line. In particular, the measurement of the size of the used used carton, for example: we often encounter a very old sample box that the customer needs to measure according to his size. Moreover, his carton was strictly calculated during the original design process, and it was used for pallets and container loading, and it was also good for protecting its products. This requires us to make accurate measurements on the sample box. The measurement of the manufacturing dimensions of the ordinary 0201 corrugated box manufactured by two different production processes is described below.

1 Measurement of the size of the 0201 type carton produced by the carton forming grooving machine

As shown in the figure: The longitudinal indentation line of the carton is at the center of the slot. If the indentation line of the carton cannot be clearly identified, it is difficult to measure its true specifications. However, we can measure the size of the slotted slot by measuring its position. It should be noted here that the position of the single-piece carton and the two-carton carton are not the same when measured. In Figure 3, we sequentially use the numbers 1-8 for the notches and trims. The longitudinal indentation line of the carton is at the center of the notch, and it can be concluded that the distance from the trim 1 to the center of the trim 2 and 3 is the length of the carton; the center of the trim 4 and 5 to the trim 6 and The distance of 7 is also the length of the carton, from which it can be inferred that the length from the cutting edge 4 to the cutting edge 6 or the cutting edge 5 to the cutting edge 7 is the length of the carton; it is also possible to calculate the cutting edge 2 to the cutting edge 4 or the cutting edge 3 to The distance between 5 is wide. In this way, a very accurate size can be obtained during the measurement process. It should be noted here that if the carton is measured in one piece or in the back of a two-piece carton, the process is generally adjusted for the aesthetics of the carton after binding, and its size is reduced, generally reduced by 2- 3mm. When measuring the size, the thickness of the grooved blade is generally 6 mm. Therefore, the distance from the cut edge 6 to the cut edge 8 in the above figure is exactly one width of the carton. * The length of the front side close to the tongue is the length of the carton from the trim 1 to the midpoint of the trim 2 and 3. The size of the carton is measured by measuring the position of the knife edge, and these details cannot be ignored.

2 Measurement of the size of 0201 corrugated box produced by carton die-cutting machine

The carton produced by the carton die-cutting machine is produced according to the design requirements. Different designs and molding methods produce different sizes. Generally, we can measure the size by measuring the indentation. Here is a typical 0201 type carton die cut pattern.

As shown in Fig. 4, the position of the indentation is greatly changed as compared with the 0201 type carton produced by the carton forming and grooving machine. The longitudinal indentation of the carton is not in the middle of the slot, but is close to the side of the front; the transverse indentation line is lower on the side than on the front. Such a carton design is designed for a more aesthetically pleasing appearance of the carton. For the measurement of the size of the carton, the exact size can be measured by measuring the indentation and the knife mark inside the carton; because the carton die-cut produces a small indentation for easy identification. Of course, the size of the knife edge can also be measured to measure its size; it is the same as the 0201 carton measurement produced by the forming slot machine, except that the position of the measurement is changed.

2. Design and calculation of corrugated box size

1 Conversion and calculation of inner diameter size, outer diameter size and manufacturing size

The conversion of the inner diameter to the outer diameter is an important part of the carton design. Customers often provide us with only the size or style of the built-in products. This requires us to calculate the outer dimensions and manufacturing dimensions of the carton; especially for containers that are transported in containers, the calculation of the outer diameter of the carton is particularly important. A good carton design can save a lot of money on transportation.

Here we first introduce the relationship between the inner diameter of the carton, the outer diameter and the manufacturing size:

As shown in Fig. 1, the length A indicates the outer diameter of the carton, the length B indicates the inner diameter of the carton, and the length C indicates the manufacturing size of the carton. The outer dimensions and inner dimensions of the carton are not difficult to understand. For the manufacturing dimensions of the carton, various references are also inconsistent. As shown in Fig. 2, it is an indentation when the carton is not folded. The upper is the inner paper and the lower is the facial paper, and there are two indentations respectively; referring to Fig. 1, we fold the cardboard, and it can be seen that the dimension D of Fig. 2 is the dimension C of Fig. 1; that is, the manufacturing size of the carton. In the process of indentation, when the corrugated corrugated corrugated board is crushed and folded over, the outer diameter of the carton is actually only a distance of two F from the manufacturing size of the carton. Corrugated cardboard has been folded at 90 degrees, and the corrugated type at the indentation has basically disappeared; therefore, when we calculate the manufacturing size and convert it into the outer diameter, we only need to make two cardboard boxes and two cardboards. The sum of the thickness of the paper is ok. Of course, the same method can be used to calculate the size of the carton.

After familiarizing yourself with the various dimensions of the carton, we can calculate the manufacturing dimensions and the external diameter with the inner diameter of the carton. However, since the corrugated board is not very flat, it will cause dimensional changes, and we will increase the size during the design process. As shown in Fig. 3, a manufacturing size and an outer diameter of a 0201 type AB cassette having a length of 50 cm, a width of 40 cm, and a height of 30 cm were designed. We first calculate the manufacturing dimensions of the carton: the thickness of AB楞 is 8mm, and the thickness of each layer of paper is 0.2mm; according to Figure 1, we can calculate the length of the carton is 51.4cm and the width is 41.4cm. Because it is a 0201 type carton produced by a common slotting machine, the longitudinal indentation line of the length and width of the carton is in a straight line. When the carton flap is closed, the inner flap is already placed inside the carton; The calculation of the height of the carton also requires the thickness of the upper and lower layers of cardboard. Therefore, the manufacturing size of the carton is 51.4 cm * 41.4 cm * 31.8 cm. The outer diameter of the carton can be sequentially pushed out: 52.4cm*41.6cm*33.4cm. It should be noted here that the thickness of the cardboard may be changed during the production process, and the thickness of a cardboard added to the tongue may be reduced after the production process; therefore, the internal space is not increased during the calculation. The height of the external warp is more varied. It is calculated according to the height of the carton in the box, so that it can meet the requirements of container packing.

2 Calculation of carton flap size

As shown in Fig. 5, the left side is the size of the 0201 corrugated box into a box; the right side is the box size diagram. From the figure we can see that due to the influence of the inner flap, the lid is not horizontal after being closed, but slightly inclined. The width of the flap is not half the width, but a little longer, so we added a magnification factor to the actual production. We can calculate this magnification factor by trigonometric function. However, due to the plasticity of the carton itself, and for ease of calculation, most manufacturers calculate a fixed amplification factor based on the thickness of the cardboard. As shown in Table 1:

Of course, such a magnification factor is only suitable for a general corrugated box; if a carton that requires a high requirement for the flap is encountered, the magnification factor of the carton cover can be found by a function. Also, the magnification factors listed in the above table are not suitable for cartons with a width of less than 20 cm. In the calculation of the flap size of some other shaped boxes, the dimensions can be calculated by the principles of Figures 1 and 2.

3 calculation of blanking specifications of carton

The cartons currently produced are mainly made of 0201 corrugated boxes, as shown in Figure 3. According to the above, we can calculate how much material is needed to put an ordinary 0201 carton into production.

Figure 3: length of cardboard = 2 times the length of the carton + 2 times the width of the carton + the tongue of the carton

Cardboard width = carton height + 2 times carton flap

According to the formula, we calculate the blanking specifications of the carton. For example, we still calculate the blanking specifications of the 0201 type AB 楞 corrugated box with a length of 50cm, a width of 40cm and a height of 30cm.

Cardboard length = 4cm + 50 cm + 50 cm + 40 cm + 40 cm = 184 cm

Cardboard width = 30 cm + 20.3 cm + 20.3 cm = 70.6 cm

Here, the net material specifications of the carton are calculated and trimmed during production. In order to save material as much as possible, the trimming size is generally no more than 1cm. The edges near the tongue do not need to be trimmed. The blanking specification is 185cm long and 72.6cm wide; we can directly cut the paperboard factory. The blanking size of the shaped box can be calculated according to the same principle, but the formulas for different box calculations are different.

In summary, the measurement and calculation of the size of the carton is indeed a very cumbersome task, but it is also an important task in the design of corrugated carton structure. A qualified carton not only needs to protect the product well, it needs a good shape; in particular, the sales package and the transport packaging function are all in one carton, and the reasonable size will be the key to the carton design. Because the change in size will directly affect the changes in the various properties of the carton. When we develop new boxes, our cartoners must strictly calculate the size of the carton so that the customer's products can be better protected. When we create value for our customers, we create a win-win opportunity with them. So, we are relieved!